Aphids (Hemiptera: Aphididae) have a repertoire of defensive behaviors against insect predators and parasitoids that includes kicking, twitching, walking away and dropping off the plant. These defensive responses, which are most effective when aphids receive early warning of an approaching predator, are often initiated before the predator reaches the aphid. Although described before, the process of predator detection has practically never been experimentally investigated in aphids and it is currently unknown whether they can distinguish approaching predators from harmless insects, and which senses they use for pre-encounter predator detection. I therefore addressed these two questions by comparing seven behavioral responses of pea aphids (Acyrthosiphon pisum) to approaching predators (ladybugs) and non-predators (variegated caper bugs), to the plant-borne vibrations they generate and to visual cues. Aphids kicked, raised their bodies, withdrew their stylets and dropped more often in response to approaching ladybugs. Visual cues elicited only antennal movements. Body raising and antennal movements were more frequent in response to ladybug vibrations compared to caper bug vibrations. I found no evidence for predator-odor detection. Stylet withdrawal (preparation for escape) and dropping occurred in response to climbing insects but not to vibrations. I conclude that pea aphids use multimodal cues to detect approaching coccinellid predators. While visual cues alert the aphid without triggering defensive responses, vibrational cues are used to distinguish predators from non-predators. Future research on vibration patterns that aphids interpret as signs of danger may lead to the development of novel management techniques for one of the world’s worst crop pests.

蚜虫（半翅目：蚜虫）具有对昆虫的天敌和寄生物的防御行为，包括踢，抽搐，走开和掉下植物。这些防御反应在蚜虫收到即将到来的掠食者的预警时最有效，通常在掠食者到达蚜虫之前就启动。尽管之前已经进行了描述，但实际上从未对蚜虫进行过天敌的掠食者探测过程的实验研究，目前尚不清楚它们是否能够将接近的掠食者与无害昆虫区分开来，以及它们是否被用于捕食天敌的感觉。因此，我谈到了比较豌豆蚜虫七种行为反应这两个问题（豌豆蚜）接近掠食性动物（瓢虫）和非掠食性动物（杂色雀毛），它们产生的植物传播的振动以及视觉提示。蚜虫踢脚，抬高身体，撤回管心针并因应接近的瓢虫而更频繁地掉落。视觉提示仅引起触角运动。与瓢虫振动相比，瓢虫振动引起的身体举起和触角运动更为频繁。我没有发现捕食者气味的证据。探针的撤回（准备逃生）和掉落是对爬虫的反应而不是对振动的反应。我得出结论，豌豆蚜虫使用多峰线索来检测即将来临的球虫捕食者。视觉提示在不触发防御反应的情况下提醒蚜虫，振动提示则用于区分捕食者和非捕食者。